During the merger many pilots were “very unhappy” about the plans, and unions encouraged workers to avoid participating in staff surveys to show contempt for the decision.

She said: “Three weeks into the merger I did a staff attitude survey, which got a 25% response rate. This was partly because union partners told employees not to fill it in. Two years ago, I couldn’t have asked for the sort of [high engagement] results we have got now.”

She also told the magazine the firm’s HR team had reduced by at least 20% since the merger, partly caused by the decision to combine the Crawley and Manchester-based teams into one central office in Luton.

“People left through natural wastage or by deciding they didn’t want to relocate,” she said. “In HR we had to harmonise policies, reduce 35 performance management frameworks into one, and we had to prepare the HR team.”

Next month TUI Travel will publish its preliminary results for the year ended 30 September 2009.